MULTIPLEXING OPTICAL SYSTEM AND FEATURE VECTOR TRANSFORMATION APPARATUS USING THE SAME; FEATURE VECTOR DETECTING AND TRANSMITTING APPARATUS; AND RECOGNITION AND CLASSIFICATION SYSTEM USING THESE APPARATUSES

A multiplexing optical system necessary for transforming input information into effective feature vectors at high speed and with high accuracy, without loss of a spatial frequency component of multiplexed object vector information, for example. Also presented are a feature vector transformation apparatus using the multiplexing optical system, and others. The multiplexing optical system performs a Fourier transform in parallel on multiplexed vector information lying in an input plane (R) as an object to be processed. The system includes a Fourier transform lens (30) for performing a Fourier transform in parallel, and satisfies the condition of (k.sub.R .lambda.f.sub.F /a<p) in an arbitrary cross-section containing an optical axis, where k.sub.R is the number of components of each multiplex portion (10, 11) of the multiplexed vector information; p is the pitch between zero-order portions of Fourier transformed information concerning adjacent multiplex portions obtained in the Fourier transform plane (F); a is an effective display size of each multiplex portion; .lambda. is the wavelength of light used; and f.sub.F is the focal length of the Fourier transform lens (30).